--genScript doesn't include nimbase.h file

[dmac]

Generating a compilation script with --genScript doesn't work out-of-the-box because the generated compilation commands don't include a path to the nimrod/lib directory.

$ cat compile_hello.sh
clang -c  -w  -o nimrod_hello.o nimrod_hello.c
clang -c  -w  -o nimrod-repo_system.o nimrod-repo_system.c
clang   -o hello  nimrod-repo_system.o nimrod_hello.o -ldl
$ sh compile_hello.sh
nimrod_hello.c:5:10: fatal error: 'nimbase.h' file not found
#include "nimbase.h"
         ^
1 error generated.
nimrod-repo_system.c:5:10: fatal error: 'nimbase.h' file not found
#include "nimbase.h"
         ^

If I'm correct in assuming that --genScript is intended to generate self-contained compileable C source, should it perhaps bundle the required header files into nimcache? Being new to nimrod, I'm not sure if nimbase.h is the only dependency or if there could potentially be others from nimrod/lib.

[reactormonk]

IIRC the nimbase.h is hardcoded, so hardcoding the bundle of that file would be an idea.

[johanobergman]

I wanted to compile some Nim code on my Raspberry Pi Zero today, and ran nim c --cpu:arm --os:linux --compileOnly --genScript src/app.nim, but the /Users/johanbergman/.cache/nim/app_d/ directory didn't contain nimbase.h, so I got an error when trying to run the compile script on my Pi.

The copying of nimbase.h was added here:

Nim/compiler/extccomp.nim

Line 471 in 37a5dab

proc generateScript(projectFile: string, script: Rope) =

but is no longer present here:
https://github.com/nim-lang/Nim/blob/devel/compiler/extccomp.nim#L412

I copied the file manually and was then able to compile on the Pi using the script in the cache dir.

Two takeaways:

• Is it possible to copy over nimbase.h automatically? It was quite a headache to figure out everything as a Nim newbie.
• It was really difficult to find out where the source files and build script are located (the cache dir). The documentation on cross compilation https://nim-lang.org/docs/nimc.html#crossminuscompilation doesn't mention it, neither does the compile command output. The .deps-file was the only file created in my current directory, so I assumed something had gone wrong.